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United States Patent |
5,592,253
|
Nishimura
,   et al.
|
January 7, 1997
|
Lock device of cartridge chamber door of camera
Abstract
A lock device of a camera using a film cartridge having a light-shielding
door shiftable between a light-shielding condition for shielding light to
a photographic film in the film cartridge and a non-light-shielding
condition for enabling the photographic film to be withdrawn from the film
cartridge, the lock device comprises a cartridge chamber having an opening
portion through which the film cartridge is loaded in the cartridge
chamber, a cartridge chamber door being disposed in a shielding position
for shielding the opening portion of the cartridge chamber when the
light-shielding door of the film cartridge is at least in the
non-light-shielding condition, a holding member shiftable between a
prohibited position for prohibiting movement of the cartridge chamber door
from the shielding position and an allowed position for allowing movement
of the cartridge chamber door from the shielding position, and a limiting
member for limiting movement of the holding member from the prohibited
position to the allowed position.
Inventors:
|
Nishimura; Tomoki (Kawasaki, JP);
Akami; Noboru (Yokohama, JP)
|
Assignee:
|
Nikon Corporation (Tokyo, JP)
|
Appl. No.:
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515568 |
Filed:
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August 16, 1995 |
Foreign Application Priority Data
Current U.S. Class: |
396/538; 396/513 |
Intern'l Class: |
G03B 017/26 |
Field of Search: |
354/174,275,277,288
|
References Cited
U.S. Patent Documents
5430515 | Jul., 1995 | Lawther et al. | 354/275.
|
5477295 | Dec., 1995 | Lawther et al. | 354/275.
|
5481325 | Jan., 1996 | Wada et al. | 354/288.
|
Foreign Patent Documents |
1191836 | Aug., 1989 | JP.
| |
5150344 | Jun., 1993 | JP.
| |
Primary Examiner: Mathews; A. A.
Claims
What is claimed is:
1. A lock device of a camera having a camera body using a film cartridge
having a light-shielding door shiftable between a light-shielding
condition for shielding light to a photographic film in said film
cartridge and a non-light-shielding condition for enabling said
photographic film to be withdrawn from said film cartridge, said lock
device comprising:
a cartridge chamber having an opening portion through which said film
cartridge is loaded in said cartridge chamber;
a cartridge chamber door being disposed in a shielding position for
shielding said opening portion of said cartridge chamber when said
light-shielding door of said film cartridge is at least in the
non-light-shielding condition;
a holding member, slidably supported by said camera body and having a
projection, shiftable between a prohibited position for prohibiting
movement of said cartridge chamber door from said shielding position and
an allowed position for allowing movement of said cartridge chamber door
from said shielding position; and
a limiting member contactable with said projection for limiting movement of
said holding member from said prohibited position to said allowed
position.
2. A lock device according to claim 1, wherein said limiting member is
driven in accordance with drive of said light-shielding door of said film
cartridge.
3. A lock device according to claim 1, wherein said limiting member
includes a detection device for generating an electric signal indicating
that said light-shielding door of said film cartridge is in the
light-shielding condition or in the non-light-shielding condition, said
limiting member being driven in accordance with said electric signal of
said detection device.
4. A camera having a camera body comprising:
a cartridge chamber for accommodating a film cartridge, said cartridge
chamber having an opening portion through which said film cartridge is
accommodated or taken out from said cartridge chamber, said film cartridge
having a light-shielding door shiftable between a closed position in which
an opening of said film cartridge for pulling in or out a photographic
film and an opened position in which said opening of said film cartridge
is opened to allow said photographic film to be pulled in and out;
a drive device for opening and closing said light-shielding door of said
film cartridge accommodated in said cartridge chamber;
a cartridge chamber door for closing said opening portion of said cartridge
chamber; and
a lock device being interlocked with said drive device for prohibiting said
cartridge chamber door from being opened when said light-shielding door of
said film cartridge is disposed in said opened position, and allowing said
cartridge chamber door to be opened when said light-shielding door of said
film cartridge is disposed in said closed position, comprising a holding
member, slidably supported by said camera body and having a projection,
and a limiting member contactable with said projection.
5. A camera according to claim 4, wherein said lock device comprises:
a holding member being engageable with said cartridge chamber door and
shiftable between a prohibited position for prohibiting said cartridge
chamber door from being opened and an allowed position for allowing said
cartridge chamber door to be opened; and
a limiting member being interlocked with said drive device for limiting
movement of said holding member from said prohibited position to said
allowed position when said light-shielding door of said film cartridge is
disposed in said opened position.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to, in a camera using a film cartridge having
a light-shielding door (light lock door) at its lead portion, a lock
device of a cartridge chamber door for preventing the cartridge chamber
door from being opened accidentally while a film is loaded in the camera.
2. Related Background Art
As shown in FIG. 1, there is a film cartridge 1 having a light-shielding
door 1c at a lead portion thereof. When a film is contained in the film
cartridge 1 in a roll, the light-shielding door 1c is closed to prevent
the film from being exposed. After the film cartridge 1 is loaded in a
camera, the light-shielding door 1c is opened to advance the film to the
inside of the camera. At that time, in order to prevent the film from
being exposed, an opening portion of a cartridge chamber is provided with
a cartridge chamber door 3.
There are cases where although the film is loaded in the camera, the
cartridge chamber door for taking out the film cartridge is carelessly
opened to expose the film after photographing.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a look device of a
camera capable of preventing a loaded photographic film from being exposed
erroneously.
In order to solve the above object, a lock device of a camera of the
present invention has a limiting member interlocked with the opening and
closing of a light-shielding door of a film cartridge so as to limit the
opening of a cartridge chamber door of the camera while the
light-shielding door of the film cartridge is opened.
According to the lock device of the camera of the present invention, the
limiting member for limited movement of a holding member for limiting the
opening and closing of the cartridge chamber door is provided. Therefore,
when the light-shielding door of the film cartridge is in a
non-light-shielding condition, even though a photographer tries to operate
the holding member to open the cartridge chamber door, the holding member
cannot be shifted to an allowed position for allowing the opening of the
cartridge chamber door, so that the cartridge chamber door will not be
opened.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a conventional film cartridge with a
light-shielding door;
FIG. 2 is a cross section showing a first embodiment of the present
invention;
FIG. 3 is a perspective view showing the first embodiment, wherein the
light-shielding door is opened;
FIG. 4 is a perspective view showing the first embodiment, wherein the
light-shielding door is closed;
FIG. 5 is a perspective view showing a second embodiment of the present
invention, wherein a light-shielding door is opened;
FIG. 6 is a perspective view showing the second embodiment, wherein the
light-shielding door is closed;
FIG. 7 is a perspective view showing a third embodiment of the present
invention, wherein a light-shielding door is opened;
FIG. 8 is a perspective view showing the third embodiment, wherein the
light-shielding door is closed;
FIG. 9 is a block diagram showing the third embodiment;
FIG. 10 is a flowchart showing the third embodiment;
FIG. 11 is a perspective view showing a fourth embodiment of the present
invention, wherein a light-shielding door is opened; and
FIG. 12 is a perspective view showing the fourth embodiment, wherein the
light-shielding door is closed.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiments of the present invention will be described hereinafter with
reference to the accompanying drawings.
FIG. 2 is a cross section showing a first embodiment of the present
invention. In FIG. 2, a film cartridge 1 is loaded in a cartridge chamber
2a of a camera body 2. A film advancing fork 8 connected to a film
advancing drive system (not shown) is engaged with a film shaft member 1a
of the film cartridge 1. A light-shielding door opening and closing fork
6a engaged with a gear train 6b connected to a film winding and rewinding
motor (not shown) is engaged with a light-shielding door opening and
closing shaft 1b of the film cartridge 1. A fixing lever gear 6c engaged
with the gear train 6b rotates a fixing lever 7 via a connecting shaft 7a.
A cartridge chamber door 3 rotates around a pivot 3a counterclockwise in
the drawing. When the cartridge chamber door 3 is closed, an end 5f of a
cartridge chamber door opening and closing lever 5 is fitted in a slot 3b
formed in the cartridge chamber door 3 to prohibit the door 3 from being
opened (in the counterclockwise direction in the drawing). The other end
of the lever 5 is connected to the camera body 2 via a spring 5a and urged
by the spring 5a toward the film cartridge 1.
FIG. 3 is a perspective view showing the first embodiment, wherein the
light-shielding door 1c is opened. When the fork 6a engaged with the gear
train 6b is rotated clockwise, the light-shielding door 1c interlocked
with the light-shielding door opening and closing shaft 1b is opened, as
shown in FIG. 3. Simultaneously, the fixing lever gear 6c engaged with the
gear train 6b rotates counterclockwise to cause the cam-shaped fixing
lever 7 to rotate counterclockwise via the connecting shaft 7a. As a
result, the fixing lever 7 is brought into contact with a projection 5c
formed on the cartridge chamber door opening and closing lever 5.
Therefore, the cartridge chamber door opening and closing lever 5 is
prevented from being withdrawn from the cartridge chamber door 3 thereby
to prevent the opening of the cartridge chamber door 3.
FIG. 4 is a perspective view showing the first embodiment, wherein the
light-shielding door 1c is closed. When the fork 6a engaged with the gear
train 6b is rotated counterclockwise, the light-shielding door 1c
interlocked with the light-shielding door opening and closing shaft 1b of
the film cartridge 1 is closed, as shown in FIG. 4. Simultaneously, the
fixing lever gear 6c engaged with the gear train 6b rotates clockwise to
cause the cam-shaped fixing lever 7 to rotate clockwise via the connecting
shaft 7a. As a result, the fixing lever 7 is detached from the projection
5c of the cartridge chamber door opening and closing lever 5, providing a
space between the projection 5c and the fixing lever 7. Therefore, in the
state of FIG. 4, a photographer can open the cartridge chamber door 3 by
grasping a claw portion 5b of the cartridge chamber door opening and
closing lever 5 with his or her fingers and sliding the lever 5 against
the force of the spring 5a to disengage the cartridge chamber door opening
and closing lever 5 from the cartridge chamber door 3.
FIG. 5 is a perspective view showing a second embodiment of the present
invention, wherein the light-shielding door 1c is opened. Elements
identical to those in the first embodiment are designated by the like
reference numerals. When the fork 6a engaged with the gear train 6b is
rotated clockwise, the light-shielding door 1c interlocked with the
light-shielding door opening and closing shaft 1b is opened, as shown in
FIG. 5. In accordance with the movement of the light-shielding door 1c, a
fixing lever fork 9a engaged with the light-shielding door opening and
closing shaft 1b rotates clockwise. Consequently, a fixing lever 9b for
rotating together with the fork 9a in the same phase rotates clockwise, so
that an end portion 9c of the fixing lever 9b presses a fixing member 12
toward the cartridge chamber door opening and closing lever 5. Thereby,
the fixing member 12 enters a groove of the opening and closing lever 5
formed between a projection 5d and the claw portion 5b. As a result, the
cartridge chamber door opening and closing lever 5 is prevented from being
withdrawn from the cartridge chamber door 3 thereby to prevent the opening
of the cartridge chamber door 3.
FIG. 6 is a perspective view showing the second embodiment, wherein the
light-shielding door 1c is closed. When the fork 6a engaged with the gear
train 6b is rotated counterclockwise, the light-shielding door 1c
interlocked with the light-shielding door opening and closing shaft 1b of
the film cartridge 1 is closed, as shown in FIG. 6. In accordance with the
movement of the light-shielding door 1c, the fixing lever fork 9a engaged
with the light-shielding door opening and closing shaft 1b rotates
counterclockwise. Accordingly, the fixing lever 9b rotates
counterclockwise to cause its end 9c to be detached from the fixing member
12. Then, the fixing member 12 is detached from the groove between the
projection 5d and the claw portion 5b of the opening and closing lever 5
due to a spring 12a connected to the camera body 2 and biased toward the
camera body 2. Therefore, in the state of FIG. 6, the photographer can
open the cartridge chamber door 3 by grasping the claw portion 5b of the
cartridge chamber door opening and closing lever 5 with his or her fingers
and sliding the lever 5 against the force of the spring 5a to disengage
the cartridge chamber door opening and closing lever 5 from the cartridge
chamber door 3.
FIG. 7 is a perspective view showing a third embodiment of the present
invention, wherein the light-shielding door 1c is opened. Elements
identical to those of the first embodiment are designated by the like
reference numerals. In FIG. 7, a switch pattern 6d is provided on the
light-shielding door opening and closing fork 6a. The opening or closing
of the light-shielding door 1c is detected by converting it into an
electric signal by means of the switch pattern 6d and a switch 10. When
the fork 6a engaged with the gear train 6b is rotated clockwise, the
light-shielding door 1c interlocked with the light-shielding door opening
and closing shaft 1b of the film cartridge 1 is opened. At this time, the
opening of the light-shielding door 1c is recognized by a light-shielding
door control circuit of a CPU (not shown) via the switch pattern 6d and
the switch 10. Immediately thereafter, the light-shielding door control
circuit projects a projection 11a of a plunger 11 provided next to the
cartridge chamber door opening and closing lever 5. Thereby, the
projection 11a of the plunger 11 fixes the projection 5e of the cartridge
chamber door opening and closing lever 5, so that the cartridge chamber
door opening and closing lever 5 is prevented from being withdrawn from
the cartridge chamber door 3 thereby to prevent the opening of the
cartridge chamber door 3.
FIG. 8 is a perspective view showing the third embodiment, wherein the
light-shielding door 1c is closed. When the fork 6a engaged with the gear
train 6b is rotated counterclockwise, the light-shielding door 1c
interlocked with the light-shielding door opening and closing shaft 1b of
the film cartridge 1 is closed, as shown in FIG. 8. At this time, the
closing of the light-shielding door is recognized by the light-shielding
door control circuit via the switch pattern 6d and the switch 10 provided
on the light-shielding door opening and closing fork 6a. Then, the
light-shielding door control circuit retracts the projection 11a of the
plunger 11, making it possible to open the cartridge chamber door 3.
FIG. 9 is a block diagram of the third embodiment. In FIG. 9, the CPU
outputs a command for projecting the projection 11a of the plunger 11 when
the switch 10 is turned on. Also, the CPU outputs a command for retracting
the projection 11a of the plunger 11 when the switch 10 is turned off.
FIG. 10 is a flowchart of the third embodiment. In the step S110, it is
judged whether the switch 10 is on. When it is on, the procedure goes to
the step S120, while when it is off, the procedure goes to the step S130.
In the step S120, the projection 11a of the plunger 11 is projected to
lock the projection 5c of the cartridge chamber door opening and closing
lever 5. In the step S130, the projection 11a of the plunger 11 is
retracted to unlock it.
Although the switch pattern 6d is provided on the light-shielding door
opening and closing fork 6a to detect the opening or closing of the
light-shielding door 1a in this embodiment, the method and means for
converting the opening or closing of the light-shielding door into an
electric signal and detecting it are not limited to the above and other
methods and means can be adopted. Also, without fixing the projection 5e
of the cartridge chamber door opening and closing lever 5 directly by
means of the projection 11a of the plunger 11, an operating member coupled
to the projection 11a of the plunger 11 may fix the projection 5e of the
cartridge chamber door opening and closing lever 5.
Further, instead of the plunger, a motor may be utilized to project or
retract the projection 11a.
FIG. 11 is a perspective view showing a fourth embodiment of the present
invention, wherein the light-shielding door 1c is opened. Elements
identical to those of the first embodiment are designated by the like
reference numerals. In FIG. 11, a cartridge fixing member 14 is engaged
rotatably with a boss portion (not shown). An end of a spring 13 is
connected to the camera body 2, while the other end thereof is connected
to a spring connecting portion 14d. The cartridge fixing member 14 is
urged by the spring 13 so as to rotate clockwise.
When the fork 6a engaged with the gear train 6b connected to the film
winding and rewinding motor (not shown) is rotated clockwise, the
light-shielding door 1c interlocked with the light-shielding door opening
and closing shaft 1b of the film cartridge 1 is opened. As the
light-shielding door 1c is opened, the fixing lever fork 9a engaged with
the light-shielding door opening and closing shaft 1b rotates clockwise.
Accordingly, the fixing lever 9b for rotating together with the fork 9a in
the same phase rotates clockwise, so that the end portion 9c of the fixing
lever 9b is brought into contact with an arm portion 14c of the cartridge
fixing member 14 and the cartridge fixing member 14 is rotated
counterclockwise. As a result, an L-shaped fixing portion 14d of the
cartridge fixing member 14 is brought into contact with a fixing surface
5f of the cartridge chamber door opening and closing lever 5. Therefore,
the cartridge chamber door opening and closing lever 5 is prevented from
being withdrawn from the cartridge chamber door 3 thereby to prevent the
opening of the cartridge chamber door 3.
FIG. 12 is a perspective view showing the fourth embodiment, wherein the
light-shielding door 1a is closed. When the fork 6a engaged with the gear
train 6b is rotated counterclockwise, the light-shielding door 1c
interlocked with the light-shielding door opening and closing shaft 1b of
the film cartridge 1 is closed, as shown in FIG. 12. As the
light-shielding door 1c is closed, the fixing lever fork 9a engaged with
the light-shielding opening and closing shaft 1b is rotated
counterclockwise. Simultaneously, the fixing lever 9b for rotating
together with the fixing lever fork 9a in the same phase rotates
counterclockwise to cause the end portion 9c of the fixing lever 9b to be
detached from the arm portion 14c of the cartridge fixing member 14. The
cartridge fixing member 14 rotates clockwise due to the force of the
spring 13, so that the L-shaped fixing portion 14d of the cartridge fixing
member 14 is disposed in an escape portion 5g. Therefore, in the state of
FIG. 12, the photographer can open the cartridge chamber door 3 by sliding
the cartridge chamber door opening and closing lever 5 against the force
of the spring 5a to disengage the lever 5 from the cartridge chamber door
3.
In the present invention, a limiting member for limiting movement of a
holding member for limiting the opening and closing of the cartridge
chamber door is provided. Therefore, when the light-shielding door of the
film cartridge is in a non-light-shielding condition, even though the
photographer tries to operate the holding member to open the cartridge
chamber door, the holding member cannot be shifted to an allowed position
for allowing the opening of the cartridge chamber door, so that the
cartridge chamber door will not be opened. That is, the photographic film
will not be exposed carelessly.
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